Semantic Matching of Web Service Policies

In this work, we present a novel approach for matching the nonfunctional properties of Web Services represented using WS-policy. To date, most policy matching has been done using syntactic approaches, where pairs of policies are compared for structural and syntactic similarity to determine compatibility. In our approach, we enhance the policies of a Web Service with semantics by creating the policy assertions based on terms from ontologies. The use of semantic terms enables richer representations of the intent of a policy and allows matching of policies with compatible intent, but dissimilar syntax. Also, in cases where policies are defined at multiple levels/domains (such as security, privacy, trust, transactional etc.), we handle inter-domain policy interactions by processing the rules represented in the semantic domain models. This helps identify any inconsistencies in policies during specification as well matching. This approach of using semantic concepts and rules during policy matching leads to better Web Service matches that may not have been possible with syntax based matchers, or prior semantic based methods.